Identifying "new" version of Canon 100-400mm f4.5-5.6L IS USM

There is no new version officially, but people noticed rather significant improvement for this lens recently. Basically, you will want one which has a date code later than UV04xx and better yet UV06xx. And there is also another more subtle signature of the newer version:



As you can see, older version of this lens has "0" and "1" as the label for the stablizer, and the new version has "on" and "off". However, given the above two signs for new version, the date code is more consistent and more reliable.

Someone suggested that the so-called new version is just tighter quality control, and actually, older version can perform as great as this so-called newer version, provided that you are lucky enough to get a good copy.

The major improvement of the new version is that, it works nearly as great (someone suggested at least 90%) as a Canon 400mm f5.6L at its 400mm end!